Electron discharge devices



March 24, 1970 E. E. BUFFINGTON 3,502,936

ELECTRON DISCHARGE DEVICES Filed July 6. 1966 OUTPUT GATE GATE

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{33 34 PARAPHASE 35 AMPLlFlER M BI STABLE FIG. 2

wvavroR EE BUFF/NGTON B) M FIG. 4

ATTORNEY United States Patent 3,502,936 ELECTRON DISCHARGE DEVICESEdward E. Butfington, Burlington, N.C., assignor to Western ElectricCompany, Incorporated, New York,

N.Y., a corporation of New York Filed July 6, 1966, Ser. No. 563,205Int. Cl. H01j 29/70 US. Cl. 31521 7 Claims ABSTRACT OF THE DISCLOSURE Anelectron discharge device modifies an input signal in accordance with adesired transform function. The input signal sweeps an electron beamover a first anode which has a shape conforming to the integral of thetransform fuot-ion. A portion of the electron beam, determined by theshape of the first anode, passes to a second anode to produce an outputsignal on the anodes. The output signal is the product of the inputsignal and the transform function.

This invention relates to electron discharge devices, and particularly,to an electron discharge device for modifying an input signal inaccordance with a desired transform function.

An object of this invention is a new and improved electron dischargedevice.

Another object of this invention is an electron discharge device havingan element with a mathematically derived dimension which may befabricated to perform one of a plurality of functions.

A further object of this invention is a new and improved broad-bandamplifier.

An additional object of this invention is a new and improved broadbandfrequency multiplier.

A still further object of this invention is a new and improvedbroad-band frequency divider.

In accordance with these and other objects, an embodiment of theinvention produces an output signal equal to an input signal multipliedby a transform function. An input signal sweeps an electron beam over afirst anode which has a shape conforming to the integral of thetransform function. A portion of the electron beam determined by theshape of the first anode passes to a second anode to produce an outputsignal on the anodes.

A complete understanding of the invention may be had by reference to thefollowing detailed description when considered in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a schematic of a broad-band amplifier embodying the invention;

FIGS. 2 and 3 show alternate anodes which may be substituted for ananode shown in FIG. 1 to produce a frequency doubler and frequencytripler, respectively; and

FIG. 4 shows an alternate anode and circuitry which may be substitutedfor an anode shown in FIG. 1 to produce a frequency divider.

An electron discharge device has two consecutive anodes 11 and 12interposed in the path of a horizontal fan-shaped electron beam 13within an evacuated enclosure (not shown). The first anode 11 has anopening 14 '(FIG. 1) through which a portion of the beam 13 passes tothe second anode 12. The beam 13 is generated by a negative electronsource 16 and spread into a substantially constant density horizontalfan shape by the electrostatic field produced by positively biasedelecrtodes 17. An input signal 18 applied to deflection plates 19controls the vertical positioning of the beam 13. An output signal 21 isproduced across resistors 22 and 23 which "ice connect the respectiveanodes 11 and 12 to a ground potential.

If the input signal 18 is F, and the output signal 21 is F then F =F Fwhere F is a transform function. The shapes of the sides 24 of theopening 14 conform to the integral of the transform function F, and theWidth of the opening 14 conforms to a complement of that integral.

In a linear amplifier, F =F K where K is the amplification constant. Theintegral of K is a function which increases linearly, and thus, theapparatus in FIG. 1 is a broad-band amplifier because of the linearlydecreasing width of the opening 14 for increasing input signals. Thisbroadband amplifier will amplify signals having a frequency range fromzero frequency to an upper frequency determined by the capacitance ofthe deflection plates 19 and transit time of. electrons between theplates 19. An amplifier with a desired nonlinear response may befabricated by making the sides 24 of the opening nonlinear. Also, if thedensity of the fan-shaped beam 13 is not constant throughout its width,the sides 24 may be made nonlinear to compensate for the nonconstantdensity.

The anode 11 may be fabricated with (1) a contoured side 26 (FIG. 2) toproduce a frequency doubler for a sinusoidal input signal, (2) anopening 27 (FIG. 3) to produce a frequency tripler for a sinusoidalinput signal, or (3) an opening 28 (FIG. 4) to produce an output signalwhich may be changed into a signal having a frequency which is one-halfthe frequency of a sinusoidal input signal. The shape of the side 26 andthe shapes of the sides of the openings 27 and 28 conform to respectiveintegrals of corresponding transform functions. Other shapes of theanode 11 may be made in conformity to the integration of transformfunctions to produce desired output signals.

In a frequency doubler, sin 2X =sin X X2 cos X wherein F =sin 2X, F =sinX and F =2 cos X. The integral of 2 cos X equals 2 sin X +C. Thus, inFIG. 2, the shape of the side 26 along a vertical axis conforms to sinX.

In a frequency tripler, sin 3X=sin X (34 sin X) wherin F =sin 3X, F sinX and F =34 sin X. The integral of 3-4 sin X equals X+sin 2X+C. Thus, inFIG. 3, the shape of one side of the opening 27 along a vertical axisconforms to X +sin 2X.

In a frequency halver,

The integral of F, equals Zn (sec %+tan Thus, in FIG. 4, the shape ofthe side of the opening 28 along a vertical axis conforms to theintegral of F In both the frequency doubler and the frequency tripler,the output signal consists of only the desired sinusoidal harmonic. Theinput frequency and any harmonic frequencies other than the desiredharmonic are small enough that they would have no adverse effect in mostapplications of the doubler and tripler. The frequency doubler andtripler multiply frequencies within the range from a small valueapproaching zero to a frequency determined by the capacitance of thedefiecti n plates 19 and the transit time of electrons between theplates 19. However, the input signal must have a predetermined amplitudeso that the beam 13 will sweep from the lower ends of the side 26 andopening 27 to the upper ends of the side 26 and opening 27.

In FIG. 4, the anode 11 with the opening 28 is connected to groundpotential and the anode 12 is connected by a resistor 31 to groundpotential. The signal 32 produced on the anode 12 conforms to afull-wave rectified signal which may be changed into a sinusoidal signal41 having a frequency which is one-half the frequency of the inputsignal 18.

The signal 32 is applied to the input of a paraphase amplifier 33 whichproduces two signals 34 and 35 which are complementary. The signals 34and 35 are applied to respective gates 37 and 38 which are alternatelyoperated by a bistable multivibrator 39 to alternately pass one of thesignals 34 or 35 to a common output. The signal 35 is applied to aninput of the multivibrator 39 to switch the multivibrator to alternatestates every cycle of the signal 35 to operate the gates 37 and 38.Alternate cycles of the respective signals 34 and 35 pass through thegates 37 and 38 to produce the sinusoidal output signal 41 having afrequency which is one-half the frequency of the input signal 18.

It is to be understood that the above-described embodiments areillustrative of the principles of the invention and that many otherembodiments could be devised without departing from the scope of thisinvention.

What is claimed is:

1. An electron discharge device for producing an output signal equal toan input signal multiplied by a transform function, which comprises:

means for producing an uninterrupted electron beam;

a first anode having a shape substantially conforming to the integral ofthe transform function and upon which a first portion of the electronbeam impinges;

a second anode located behind the first anode in the path of theelectron beam and upon which an unobstructed portion of the electronbeam impinges; and

means for deflecting the electron beam in accordance with the inputsignal to produce the output signal on one of the anodes, said electronbeam impinging on a first area of the first anode and a second area ofthe second anode, said first and second areas having a dimensionconforming to the shape of the first anode.

2. An electron discharge device as defined in claim 1, wherein:

the electron beam is fan shaped;

the first anode has an opening wherein a side of the opening conforms tothe integral of the transform function and upon which the first portionof the electron beam impinges.

3. An electron discharge device as defined in claim 1, wherein:

the shape of the first anode is varied to compensate for nonlinearity ofthe electron beam.

4. A broad-band amplifier including the elements of claim 1, wherein:

the electron beam is fan shaped; and

the first anode has a linearly increasing dimension upon which the firstportion of the electron beam impinges.

5. A frequency multiplier including the elements of claim 1, wherein:

the input signal is sinusoidal;

I the electron beam is fan shaped; and

the first anode has an opening wherein a side of the opening conforms tothe integral of the transform function and upon which the first portionof the electron beam impinges.

6. A frequency divider comprising the elements of claim 1, wherein theinput signal is sinusoidal and the deflecting means produce an outputsignal which is changed by the following elements into a signal having afrequency which is one-half the frequency of the input signal:

a paraphase amplifier having an input connected to one of the anodes forproducing two complementary signals on respective outputs of theamplifier; and cans connected to the respective outputs of the amplifierfor alternately passing cycles of the complementary signals to aterminal to produce the sinusoidal signal having a frequency which isone-half the frequency of the input signal.

7. A frequency divided as defined in claim 6, wherein the alternatelypassing means comprises:

a first gate connected between a first output of the amplifier and theterminal;

a second gate connected between the second output of the amplifier andthe terminal; and

a bistable multivibrator having an input connected to the firstamplifier output and having respective outputs connected to the firstand second gates for alternately operating the first and second gatesevery cycle of the signal on the first amplifier output to alternatelypass cycles of the complementary signals to the terminal to produce asinusoidal signal having a frequency which is one-half the frequency ofthe input signal.

References Cited UNITED STATES PATENTS Castanera 315-21 X RODNEY D.BENNETT, 111., Primary Examiner BRIAN L. RIBANDO, Assistant.ExaminerUS.- C X.R.. 31386

